The Science Of Breathing: How Slowing It Down Can Make Us Calm And Productive

If you’re feeling stressed, the advice to “take a deep breath” is as cliché as it comes. But even if you know that slowing your respiratory roll really can calm you down and make you feel rested and relaxed, few people know how this process actually works.

The answer all comes down to the autonomic nervous system. That is, the part of the nervous system that runs on autopilot (“autonomic” basically means “automatic”), without us consciously having to think about it. Things like digestion, heart rate, and… yes… breathing. One of the chief roles of the autonomic nervous system is to quickly and efficiently respond to danger by turning our internal dials up and down. Come into contact with a tiger in the wilderness, and your so-called "fight-or-flight" system (scientists call that the “sympathetic nervous system”) cranks into action and your heart rate goes through the roof, while a bunch of other related bodily functions kick into gear. Everything looking safe and secure? Your autonomic nervous system will enter a state of rest and relaxation (the system at work here is called the “parasympathetic nervous system”), and you’ll be able to sit still and hold a conversation.

What’s important to understand about the autonomic nervous system is that it’s… well… automatic. We can think to ourselves that we want to lift our arm in the air or stick out our tongue and have little trouble doing so. But you can’t directly slow your heart rate or shut off your digestion just be wishing and willing.

This is key to understanding stress and anxiety, and why it can be so difficult to feel calm. When we sense danger and threats (in the modern world, this is more likely to take the form of an impending deadline as anything that can physically hurt us), our autonomic systems respond automatically, and controlling them is no easy feat.

But it is possible, and breathing is key to doing so. What a lot of people don’t understand about the autonomic nervous system is how closely linked all of its disparate functions are. It is unlikely that your heart rate will enter the sympathetic fight-or-flight state without other bodily functions joining it. So if you can somehow get one of these systems to leave the stressed state and enter one of calm, the rest will often follow.

Now, as I mentioned before, most autonomic systems are completely outside our control. Your digestion and heart rate just sort of happen (and with good reason: it would be hard to go to sleep if you had to consciously think about making your heart beat). In fact, as far as autonomic systems go, there is exactly one exception to this rule: Breathing.

Breathing is special in that it is both an autonomic system that ticks along when we don’t think about it, but also a voluntary function that we can consciously control. You breathe when you sleep, but you can also choose to hold your breath or change your breathing pace. And because all of our autonomic systems are so closely linked, slowing down your breathing to a state associated with being rested and relaxed is likely to cause a cascade effect in which the rest of your autonomic nervous system responds in kind.

This is why slow, deep breathing is so powerful: It effectively hacks into your nervous system, and causes the whole thing to change its state to one of calm. If you’ve ever practiced yoga, you’ve breathed slowly with this goal in mind (although the explanation you were given as to how it works was probably a bit less precise).

Part of the reason slow breathing can affect so many other bodily systems has to do with its ability to activate the vagus nerve: A winding cranial nerve that exits the brain and interfaces with the heart, lungs, and digestive tract; and links together all of these disparate autonomic functions. The vagus serves as a sort of neural brake, slowing down your entire system. Slow exhalations, in particular, activate this nerve, and cause your entire autonomic nervous system to basically chill out.

According to Patricia Gerbarg, Ph.D., an assistant clinical professor in psychiatry at New York Medical College and co-author of The Healing Power of the Breath, the easiest way to take advantage of these physiological systems in service of calm is to simply slow down your breathing rate. For maximum relaxation and productivity, she suggests bringing things down to between four and a half and six full breaths per minute, with equal-length inhalations and exhalations. This method, which is known as Coherent Breathing, has been linked to an increase in cognitive performance and a decrease in stress.

"What's amazing about Coherent Breathing is that it doesn't just calm the body, it also calms the mind," Gerbarg says. "The sweet spot of about five breaths per minute creates an ideal state of calm alertness wherein the mind is clearer than usual. I teach students and post-grads to use it before taking tests or giving a presentation."

Of course, actually pulling off this sort of breathing can be a challenge. Gerbarg suggests starting small, with five-minute sessions when you're feeling particularly stressed. With a bit of practice, you should be able to do it for longer periods while breathing ever slower.

Gerbarg also notes that, unlike some paced breathing techniques, Coherent Breathing can be done discretely without others noticing—making it ideal of use in stressful open offices, or even in the middle of meetings.

Making things easier are numerous breathe-pacing apps that are now available for mobile devices. The best and easiest one that I've tried actually comes built into the Apple Watch as of the recent release of watchOS 3. Apple’s Breathe app is free and incredibly easy—and discreet—to use. Once loaded from the Apple Watch home screen, a flower-like animation fills the watch face, and users are directed to inhale as it grows and exhale as it shrinks. This animation makes it easy to visualize your lungs expanding and contracting. If you’re trying to make slow-breathing sessions a habit, the app also makes it easy to preschedule sessions and set reminders, and ties nicely into the iPhone’s central Health app hub.

Breathing is a powerful tool for manipulating your entire nervous system. And by understanding the specific mechanisms for how it works, I hope that people understand that it is a true physiological process, and doesn't require faith in any sort of New Age ideas. In other words: Even if you want nothing to do with concepts such as "mindfulness" and "yoga", simple changes in breathing can be a powerful tool for overcoming the stress and anxiety that fills all of our lives. And thanks to new technology, this is easier than ever.

I'm a New York-based writer and entrepreneur. I appear on a few shows on the Travel, Science, History, Discovery, and Nat Geo channels. I also write for numerous publications, including Forbes. As a writer, I'm interested in the intersection between technology, human experie...